How to Change Water Pumps on 1988 Dodge 350 Vans

Dodge came out with three different engines in 1988, but the most widely used is the 5.9-liter engine with a four-barrel carburetor. Signs of a failing water pump include a wobble in the shaft that transmits to the fan and a leak from the weep hole on the bottom of the water pump. Water pump replacement is straightforward and easily accomplished by a do-it-yourselfer. An out of balance or bent fan will quickly destroy a water pump shaft bearing, causing a leak. Attention to detail when cleaning the mating surfaces is important to the successful sealing of the pump.

Instructions

Removal

1

Slide the drain pan under the radiator petcock. Open the petcock and allow the coolant to drain. Remove the radiator cap to allow for quicker draining. Dispose of the antifreeze in an appropriate manner.

2

Loosen the clamp on the upper radiator hose at the radiator with the flat-head screwdriver. Pry the hose off the radiator with the flat-head screwdriver. Remove the overflow tank with a ratchet, extension and socket. Remove the fan shroud mounting nuts. Position the fan shroud out of the way.

3

Remove the top radiator support bracket screws for the radiator with a ratchet and socket. If the van has air conditioning, remove the air conditioning condenser screws. You can reach them by sticking the extension and socket through the front grille. Do not disconnect the air conditioning lines.

4

Raise the van with the floor jack and support it with jack stands. Disconnect the transmission cooler lines with a line wrench. Plug the ends of the lines with a cap and position them so transmission fluid doesnt leak.

5

Brace the radiator from falling forward. Remove the lower mounting screws. Remove the radiator from the van. Raise the van and remove the jack stands. Lower the van. Remove the negative battery cable with a wrench. Loosen but do not remove the four cooling fan bolts with a wrench.

6

Loosen the alternator mounting bolt and the adjusting arm bolt, using a socket. Rotate the alternator toward the center of the engine to loosen tension on the belt. Remove the belt. Loosen the three bolts in the elongated adjusting slots on the power steering pump bracket using a socket. Turn the power steering pump adjusting bolt counterclockwise to decrease tension on the belt. Lift the belt off the pulleys.

7

Remove the air compressor belt. If your van is so equipped, loosen the idler pulley adjusting bolt. Stick a prybar between the pulley and the engine and rotate the idler pulley toward the center of the engine to loosen the tension and remove the belt. If your van does not have an idler pulley, the air compressor runs on the alternator belt, which you have already removed.

8

Unplug the alternator wiring harness connector. Remove the power wire nut with a wrench and pull the power wire off. Put the nut back onto its stud. Remove the alternator bracket bolts with a socket, then remove the alternator and bracket assembly. Remove the four fan bolts and remove the fan blade, spacer and pulley as an assembly. Set the fan down with the shaft pointing upward so the silicone doesnt drain into the drive bearing.

9

Loosen the hose clamps on the hoses at the water pump with the flat-head screwdriver. Pull the hoses off the pump. Remove the water pump-to-compressor bracket bolts and the bracket with a ratchet and socket. Leave the air compressor lines attached. Move the air compressor and bracket out of the way. Remove the water pump bolts with a ratchet and socket. Tap the nose of the water pump with the palm of your hand to break it free.

Installation

10

Clean the water pump-mating surface with a scraper and shop rags. Coat the mating surface on the new water pump with a thin layer of RTV silicone. Allow the silicone to set up for two minutes. Press the gasket into the silicone. Allow the gasket to set for at least five minutes. Coat the outside of the gasket with a 1 mm bead of RTV silicone. Allow the silicone to skin over. When you touch it with your finger, the silicone should not stick to your finger.

11

Install the water pump and torque the bolts to 30 foot-pounds. Reinstall the hoses on the water pump and tighten the clamps. Reinstall the air compressor bracket and torque the bolts to 30 foot-pounds. Reinstall the fan, spacer and pulley assembly and torque the bolts to 17 foot-pounds. Reinstall the alternator. Plug in the wiring harness connector and reinstall the power wire. Tighten the nut snugly. Do not overtighten the power wire nut or you will break the stud.

12

Reinstall the accessory drive belts. To tighten tension on the belts, pull the accessory away from the engine. When the belt deflects one-quarter inch, tighten the bolts. Reinstall the radiator. Reinstall the radiator hoses and the fan shroud.

13

Close the petcock. Fill the radiator with a 50-50 premixed antifreeze. Start the vehicle and allow it to come to operating temperature. Top off the radiator as needed. Install the radiator cap. With the transmission in park, pull the transmission dipstick and wipe it off. Insert the dipstick and withdraw it again. Add Dextron II to bring the level to the full mark. Pour the transmission fluid into the dipstick tube using a funnel.